摘   要：为了更深入了解C50混凝土组成材料与孔结构对混凝土耐久性的影响，通过压汞法、快速冻融法、美国电量法、干湿循环腐蚀法等试验方法分析了复合矿物外加剂和引气剂单掺及双掺对C50混凝土孔结构与耐久性的影响规律。结果表明，对于C50混凝土,单掺复合矿物外加剂对孔隙率的影响较小，但其中无害孔比例增加，少害孔、有害孔、多害孔的比例则减少，这对抗渗性、抗腐蚀性较为有利，但对抗冻性的改善不明显；掺入引气剂可以增加混凝土闭口孔隙率，对混凝土抗冻性明显有利,但由于增加了20nm以上的开口孔，其抗渗性、抗腐蚀性有所降低；双掺时，虽增加了混凝土孔隙率，但可以使混凝土的孔径分布比单掺引气混凝土时相对合理，因而对混凝土抗冻性、抗渗性、抗腐蚀性均有利。

Abstract： In order to better understand the influence of composition materials and pore structure of C50 concrete, the tests by using mercury intrusion method, rapid freeze-thawing method, American coulometric method, dry-wet cycling corrosion method, etc. have been done for investigating the influence of adding compound mineral admixture and air entraining agent, alonely or together, on the pore structure and durability of C50 concrete, then the influence law was analysed. The test results show that, for C50 concrete, the compound mineral admixture has little effect on porosity, but the proportion of harmless pores to the whole pores is increased, while the proportion of slightly harmful, harmful and more harmful pores are decreased, which will favorablely influence on impermeability and corrosion resistance of concrete, however, the effection on forst resistance is not obvious. When adding air entraining agent, the porosity of closed pores in concrete is increased, which has favorable influence on frost resistance, but the impermeability and corrosion resistance will be decreased since the quantity of opening pores (﹥20nm) are increased. When adding both , although the porosity of concrete is increased, the pore size distribution of concrete will become more reasonable than alonely adding air-entraining agent. And this is favorable for impermeability, frost resistance and corrosion resistance of concrete.